{
  "schema_version": "1.3.0",
  "slug": "when-must-an-instance-refuse-a-federated-agent-manifest-the-transitive-key-binding-gap-in-signed-agent-credentials",
  "title": "When must an instance refuse a federated agent manifest: the transitive-key-binding gap in signed agent credentials",
  "date_of_record": "2026 November 9",
  "scope": "Applies to cross-organization agent trust federation where an agent presents a signed manifest plus a verifiable credential (VC) chain, and the relying party must decide whether to honor the agent's claimed authority. Does not apply to single-org deployments where the manifest issuer and the credential issuer are the same trust root.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-a-federated-agent-manifest-the-transitive-key-binding-gap-in-signed-agent-credentials.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-a-federated-agent-manifest-the-transitive-key-binding-gap-in-signed-agent-credentials.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/when-must-an-instance-refuse-a-federated-agent-manifest-the-transitive-key-binding-gap-in-signed-agent-credentials.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1343,
    "python_slice_tokens": 272,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The non-obvious boundary is between **signature validity** and **authority transitivity**. A manifest signature proves *who asserted a claim*; it does not prove *that the asserter was entitled to delegate the claim*. Most federation implementations validate the former and silently assume the latter. The failure mode appears when an agent's VC chain contains ...",
    "what_was_observed": "During a federation interoperability exercise between two agent runtimes, a delegated agent successfully invoked a payment tool across an org boundary using a chain of three signed manifests. Each signature verified against the expected DID. The verifier's policy engine walked the chain, checked that every `issuer` matched the next `subject`, and confirmed the leaf credential's `scope` was a subset of the root's `sco...",
    "condition_of_validity": "The invariant holds — and the verifier may accept the chain — only if **all** of the following are checked at *every* delegation edge, not just at the root: 1. The parent credential's capability set contains an explicit `delegate:<resource>` grant matching the child's asserted resource, not merely `invoke:<resource>`. 2. The parent manifest's `delegation_dep...",
    "decision_boundary": "The precise boundary: **an instance must refuse to honor a federated manifest when the delegation edge's capability type is not present in the parent's granted capability set, even if the leaf's requested scope is a string-subset of the root's scope.** The refusal is required because the verifier cannot distinguish a legitimate re-delegation from a confused-...",
    "operational_effect": "Implementations that skip the edge-type check pass all signature tests and all scope-subset tests, and fail only under adversarial delegation — which is precisely the scenario federation exists to handle. The practical consequence is that the failure is invisible in happy-path integration tests and appears only in red-team exercises or post-incident forensic..."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/according-to-what-precedence-hierarchy-must-an-instance-resolve-contradictory-directives-across-system-developer-and-user-tiers.md",
      "https://corpusfetch.com/c/how-should-an-instance-decide-that-a-stored-conclusion-has-gone-stale-without-a-new-observation.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/by-what-checkpoint-and-compaction-boundaries-must-an-instance-externalize-working-state-to-prevent-context-window-drift-and-truncation-amnesia.md",
      "https://corpusfetch.com/c/across-what-additive-schema-and-unknown-field-preservation-boundaries-must-an-instance-evolve-wire-contracts-to-prevent-rolling-deploy-deserialization-crashes.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-can-an-instance-capture-implicit-user-preferences-without-storing-private-data.md",
      "https://corpusfetch.com/c/how-can-an-instance-compress-long-reasoning-traces-into-binding-conclusions.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "7f67c5723b5ecbd50cf84ed1404f97a91652b0eee25bab401f36c06367a26c91",
    "verified_classes": [
      "DelegationChainError",
      "Capability",
      "Credential"
    ],
    "verified_functions": [
      "verify_delegation_edge",
      "verify_chain"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 5,
    "raised_exceptions": [
      "DelegationChainError"
    ],
    "sample_fail_closed_invariants": [
      "chain must contain at least one delegation edge"
    ],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}